Multishell

Install multiple versions of shells, allowing you to test against each version.

To use in your system:

    sudo add-apt-repository ppa:team-mayhem/multishell
    sudo apt-get update
    sudo apt-get install bash-3.2.0 # or any other specific version

Binaries are installed in /usr/bin, like /usr/bin/bash-3.2.0.

To use this in Travis CI, edit your travis.yml and add:

    env:
      - SHELLS="bash2.05b bash3.0.16 bash3.2.48 bash4.2.45"
    before_install:
      - echo | sudo add-apt-repository ppa:team-mayhem/multishell
      - sudo apt-get update -qq
      - sudo apt-get install -qq $SHELLS
    script: bash multishell

Contents of the multishell script:

    #!/bin/bash
    status=0

    for b in $SHELLS; do
        echo
        echo ==================
        echo $b
        echo ==================
        $b test.sh || status=$?
    done

    exit $status

This idea and the above sample code are taken from Aron Griffis. His PPA also does this same thing with far fewer shells. I've found that there are differences even among very minor version number changes, thus this PPA was created.

    http://arongriffis.com/2013/03/25/bashes.html
    https://launchpad.net/~agriffis/+archive/ubuntu/bashes/+packages